1. Field
The field relates to a pixel and an organic light emitting display device using the same, and more particularly, to a pixel capable of compensating for the threshold voltage and mobility of a driving transistor, and an organic light emitting display device using the same.
2. Description of the Related Technology
Recently, various types of flat panel display devices having less weight and volume than cathode ray tubes have been developed. The flat panel display devices include liquid crystal display devices, field emission display devices, plasma display panels, organic light emitting display devices, and the like.
Of these flat panel display devices, the organic light emitting display device displays images using organic light emitting diodes (OLEDs) that emit light through recombination of electrons and holes. The organic light emitting display device has a fast response speed and is driven with low power consumption.
Generally, an organic light emitting display device expresses a gray level and controls the amount of current that flows into an organic light emitting diode using a driving transistor included in each pixel. In this case, the luminance of different pixels in a displayed image may vary due to the threshold voltage and mobility variations of the driving transistor included in each of the pixels.
In order to solve such a problem, a method has been proposed in Korean Patent Publication No. 10-2007-0112714. In the method, the threshold voltage and mobility of a driving transistor are compensated by changing the electric potential of a first power source supplying current to an organic light emitting diode into a first electric potential (high electric potential) and a second electric potential (low electric potential).
However, when the potential of the first power source, which is a power supply voltage, is changed, a circuit component such as a filter is additionally used. Further, high heat is generated, and therefore, a heat sink is used.